fix: copy nil slices correctly in DeepCopy (#3944)

block · Jan 8, 2025 · 33abdd2 · 33abdd2
1 parent d7895a1
commit 33abdd2
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Showing 2 changed files with 11 additions and 5 deletions.
diff --git a/common/reflect/reflect.go b/common/reflect/reflect.go
@@ -143,7 +143,7 @@ func copyAny(src any, ptrs map[uintptr]any, copyConf *copyConfig) (dst any) {
 		reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
 		reflect.Uint64, reflect.Uintptr, reflect.Float32, reflect.Float64,
 		reflect.Complex64, reflect.Complex128, reflect.Func:
-		dst = copyPremitive(src, ptrs, copyConf)
+		dst = copyPrimitive(src, ptrs, copyConf)
 	case reflect.String:
 		dst = strings.Clone(src.(string))
 	case reflect.Slice:
@@ -167,9 +167,6 @@ func copyAny(src any, ptrs map[uintptr]any, copyConf *copyConfig) (dst any) {
 }
 
 func copyList(src *list.List, ptrs map[uintptr]any, copyConf *copyConfig) *list.List {
-	if src == nil {
-		return nil
-	}
 	dst := list.New()
 	for e := src.Front(); e != nil; e = e.Next() {
 		copiedValue := copyAny(e.Value, ptrs, copyConf)
@@ -178,7 +175,7 @@ func copyList(src *list.List, ptrs map[uintptr]any, copyConf *copyConfig) *list.
 	return dst
 }
 
-func copyPremitive(src any, ptr map[uintptr]any, copyConf *copyConfig) (dst any) {
+func copyPrimitive(src any, ptr map[uintptr]any, copyConf *copyConfig) (dst any) {
 	kind := reflect.ValueOf(src).Kind()
 	switch kind {
 	case reflect.Array, reflect.Chan, reflect.Interface, reflect.Map, reflect.Pointer, reflect.Slice, reflect.Struct, reflect.UnsafePointer:
@@ -194,6 +191,9 @@ func copySlice(x any, ptrs map[uintptr]any, copyConf *copyConfig) any {
 	if kind != reflect.Slice {
 		panic(fmt.Sprintf("reflect: internal error: type %v is not a slice", kind))
 	}
+	if v.IsNil() {
+		return x
+	}
 
 	size := v.Len()
 	t := reflect.TypeOf(x)

diff --git a/common/reflect/reflect_test.go b/common/reflect/reflect_test.go
@@ -88,6 +88,12 @@ func TestCopyStructOfPointers(t *testing.T) {
 	}
 }
 
+func TestNilTypeCopyIsNil(t *testing.T) {
+	assert.Assert(t, DeepCopy([]int(nil)) == nil)
+	// TODO: fix map, and all "panic: assignment to entry in nil map" failures this fix will cause
+	// assert.Assert(t, DeepCopy(map[string]int(nil)) == nil)
+}
+
 func testEqualityOfStruct(t *testing.T, expected, actual *structOfPointers) {
 	t.Helper()
 	if expected == nil || actual == nil {